Library device and inclination correction method of movable unit provided in library device

A method of correcting an inclination of a movable unit provided to a library device, the library device including a storage shelf that includes storage units aligned in a plurality of columns;

• and a conveying robot that grasps and conveys cartridges stored in the storage units, and the movable unit including a grasping unit and moving on a base board provided to the conveying robot, the method comprising:
• measuring an inclination value with respect to each of the aligned columns;
• calculating correction values of heights of one end and/or another end of the base board with respect to each of the aligned columns based on the inclination value measured in the measuring;
• and
• adjusting the heights of the one end and/or the another end of the base board according to correction values calculated in the calculating,
• wherein the base board is located to face the plurality of columns, one end of the base board being supported movably up and down by a first support post, and another end of the base board is supported movably up and down by a second support post,
• each of the first support post and the second support post includes a part where a first engagement portion is formed that is engaged with a second engagement portion provided to the base board and supports the base board, and
• the first support post is driven by a first motor and the second support post is driven by a second motor.